Study On The Effect Of Environmental Conditions On Corona Aging Characteristics Of Silicone Rubber Materials With Different Proportions

As composite insulators are widely used in power transmission and distribution lines,their own aging problems also need to be paid attention to.Therefore,this paper studies the corona aging characteristics of silicone rubber materials with different proportions in three environments.In this paper,the parameters of the aging electrode in the laboratory are determined by simulation calculation,and the environment of high humidity,salt spray and haze is simulated.The three types of silicone rubber materials are subjected to 100h corona aging in the three environments.In a high-humidity environment,the number of pulses in a cycle is 1487,of which the number of positive half-cycle pulses is less,the discharge energy is 79.5m J,and the ozone concentration is about 20ppm;the number of pulses in a salt fog environment is similar to that of high humidity,and the positive half-cycle pulse amplitude Significant increase,the discharge energy increased to 84.1m J,and the ozone concentration was about 25-30ppm;in the haze environment,the number of pulses was reduced to 682,but the number of positive half-cycle pulses was more and the pulse amplitude was larger,and the discharge energy increased to 73.3 m J,the ozone concentration is about 35ppm.The test results of the same type of material in different environments after aging show:high humidity environment to salt fog environment to haze environment,the environment gradually deteriorates,the corona aging degree of the material is getting more and more serious,and the hydrophobicity of the surface of the material is worse.The surface morphology damage is intensified,the number and width of cracks increase,the number of damaged groups in the polymer increases,the trap energy level gradually increases,the dielectric loss increases correspondingly,and the insulation performance decreases.This rule is positively correlated with the discharge energy and ozone concentration measured in the experiment,as well as environmental factors.The salt spray environment has a higher conductivity and the haze environment contains a lot of suspended particulates.The test results of samples after corona aging of different formulation materials show that:after corona aging in high humidity environment,the static contact angle of type A is the largest,the hydrophobic performance is the best,the surface crack width is the smallest,and the atomic percentage change of oxygen atoms is the smallest.,The number of Si-O-Si groups and Si-CH₃groups is the largest,and the main chain and side chain are relatively preserved the most complete.Type A is most suitable for operation in this environment.In the salt spray environment,the conductivity increases,and the bombardment effect of electrons on the surface of the material is more serious.After aging,the hydrophobicity and microscopic surface morphology of the B material are similar to those of the A,with fewer surface cracks,smaller width,and white surface There is less crystallization,and the main chain and side chains of B materials are relatively well preserved,so B materials should be selected in this environment.In the haze environment,part of the electric charge will drive the tiny suspended particles to bombard the surface of the material and attach to the surface of the material and the crack holes on the surface.The loss of hydrophobicity of Class A materials after aging in a haze environment is the most serious,the surface cracks and attachments are relatively minimal,and the main chain and side chains on the surface are the most complete.Although the performance of Class A hydrophobicity is not good,the chemical structure of Class A is relatively complete and the surface attachment is the least,and it is the least likely to cause pollution flashover.Therefore,Class A materials are most suitable for operation in haze environment.In general,the higher the content of silica gel in most environments,the lower the content of aluminum hydroxide and the worse the anti-corona aging ability.This research can provide reference for the production,operation and maintenance of composite insulators.